"Tim Young [Elevate Software]" <timyoung@elevatesoft.com> wrote in
news:5D2C4CBA-0AA8-422F-B1F7-64C9FFAB7009@news.elevatesoft.com:

> It's the standard exception object used by Delphi for string to
> <datatype> exceptions.
>

Thanks for that, Tim, but can you see why my SQL should give that error
in this case? I like to understand errors that I throw, so I can avoid
them if possible.

SELECT loyNum
 FROM LoyersDus, Locations
 WHERE (loyLocation = locNum)
 AND (
      ((locDateFin <> NULL) AND
       (loyDate > CAST(CAST(EXTRACT(YEAR,locDateFin) AS CHAR(4))+
        '-'+CAST(EXTRACT(MONTH,locDateFin) AS CHAR(2))+
        '-01' AS DATE)))
      OR
      ((locDateDebut <> NULL) AND   
       (loyDate < CAST(CAST(EXTRACT(YEAR,locDateDebut) AS CHAR(4))+  
        '-'+CAST(EXTRACT(MONTH,locDateDebut) AS CHAR(2))+
        '-01' AS DATE))
     )

I've checked locDateDebut and locDateFin visually by doing a SELECT
DISTINCT <DateField>..WHERE <DateField> <> NULL ORDER BY 1 for each date
in turn, and all the values appear correct.

There are NULL values for locDateFin, so is it possible the order of
testing is not left-to-right in the SQL? Could that cause it?

--
Chris

Chris,

<< Thanks for that, Tim, but can you see why my SQL should give that error
in this case? I like to understand errors that I throw, so I can avoid them
if possible. >>

Well, I looked at the DBISAM code, and for some reason we're doing
short-circuit evaluation, but it's doing it right-to-left and not
left-to-right.  I'm not sure why this was done this way at this point, but
there may be a reason so I'm going to have to withhold a decision on a
change until I can examine it in more detail.

--
Tim Young
Elevate Software
www.elevatesoft.com

"Tim Young [Elevate Software]" <timyoung@elevatesoft.com> wrote in
news:7B4D5D9B-9B47-4192-840D-F57FE68ED9A0@news.elevatesoft.com:

> Well, I looked at the DBISAM code, and for some reason we're doing
> short-circuit evaluation, but it's doing it right-to-left and not
> left-to-right.  I'm not sure why this was done this way at this point,
> but there may be a reason so I'm going to have to withhold a decision
> on a change until I can examine it in more detail.
>
Thanks.

I really appreciate the thoroughness of your support, particularly as I'm
not yet paid up - hopefully I'll be getting this application out the door
soon, so I can justify buying my copy of DBISAM!

--
Chris

Chris,

<< I really appreciate the thoroughness of your support, particularly as I'm
not yet paid up - hopefully I'll be getting this application out the door
soon, so I can justify buying my copy of DBISAM! >>

No problem.  Many customers use the trial for development and pay when ready
to ship.  We're a very small shop and we know how tight money can be at
times.

--
Tim Young
Elevate Software
www.elevatesoft.com